Valve structure



Oct. 22, 1940. R. H, DAKSLEAY 2,218,983

VALVE- STRUCTURE Filed Oct. 14, 1937 INVENTOR M A TTORNE Y5,

Patented Oct. 22, 1940 UNITED STATES VALVE STRUCTURE Robert H. Daisley, Birmingham, Mich, assignor' to Eaton Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application October 14, 1937, Serial No. 169,009 9 Claims. (01, 123-188) this general character having certain new and iii) novel features of construction as well as to a method of making such valves.

Objects of the invention include the provision of a hollow poppet valve initially formed as a plurality of independently formed parts at least two of which are permanently secured together in a novel manner; the provision of a hollow poppet valve in which the outer face of the valve head is initially formed independently of the main body portion of the valve and thereafter permanently sealed and secured to it by means of an interposed portion formed of a material relatively resistant to the flow of heat therethrough, the head portion and the main body portion being so constructed and arranged as to provide for the direct flow of heat between them independently of the interposed portion; the provision of a hollow poppet valve having an outer head or cover portion initially formed independently of the main body portion of the valve and permanently sealed and secured thereto in the final product by means of a third portion formed of a material having a low coefiicient of heat transfer and forming a valve seating surface for the valve, the cover portion and the main body portion being directly connected to one another through one or more areas of contact between them whereby to provide a direct path of heat transfer between them independently of said material; the provision of a valve of the general type described in which means are provided for locking the cover portion to the main body portion independently of the bond between them and the sealing portion; and the provision of a valve of the general type described in which the cover portion and the main body portion are internally welded directly together independently of the material forming the valve seating surface whereby to minimize the function of such material in securing the cover and main body portions together.

Further objects of the invention include the provision of a hollow poppet valve having heat interchange ribs or fins formed internally thereon; the provision of a hollow poppet valve internally providedwith a coolant which is fiowable at normal operating temperatures and having heat interchange fins or ribs formed internally thereof whereby to more readily effect a transfer of heatv from the head portion of the valve to the coolant; the provision of a hollow poppet valve of the type adapted to receive an internal coolant, the poppet valve being internally provided in the head portion thereof with heat interchange ribs or fins which not only serves to strengthen the valve but also serves to increase the rate of heat transfer between the head portion of the valve and the stem portion thereof through the intermediary of the coolant; the provision of a hollow poppet valve of the type adapted to receive an internal coolant, the poppet valve having internal ribs or fins in the head portion thereof; the provision of a poppet valve of hollow construction in which the outer head portion of the valve is initially formed independently of the main body portion thereof and is thereafter permanently secured thereto through the intermediary of a third portion formed of a material having a relatively low coefficient of heat transfer, the outer head portion and the main body portion of the valve being internally provided with ribs or fins which ribs or fins are intimately secured to one another in direct heat conducting relationship independently of said third portion.

Further objects of the invention include the provision of a method of making avalve comprising forming a hollow main body portion and a top covering portion therefor independently of one another, effecting a weld between portions of said main body portion and said cover to provide a permanent and direct connection between them as well as to provide a direct path of heat interchange between such portion, and further permanently securing such portions together by centrifugally distributing a molten mass of material between said portions; the provision of a method of making hollow poppet valves including the steps of independently forming a hollow main body portion open at one end and a cover therefor, at least one of the portions being internally provided with webs or fins, and thereafter securing said portions together in permanent relationship; the provision of a method of making a hollow poppet valve including the steps of independently forming a main hollow body portion having a circular outwardly flared open ended head por tion, and a circular cover portion, providing an axially projecting concentric interrupted or con tinuous ring or flange on one of said portions inwardly spaced from the periphery thereof, permanently securing said portions together by per: cussion or other welding through said ring or flange, and thereafter centrifugally distributing a moltenmass of material within said head portion serving to further permanently secure said portions together and when cooled to provide means for forming a valve seating portion of special characteristics.

The above being among the objects of the present invention the same consists in certain novel features of construction, combination of parts, and step or steps of operation to be hereinafter described with reference to the accompanying drawing, and then claimed, having the above and other objects in view.

in the accompanying drawing which illustrates suitable embodiments of the present invention and in which like numerals refer to. like parts throughout the several diiferent views,

Figure l is a fragmentary, partially broken, partially sectioned View taken centrally through the head portion of a valve structure embodying the present invention;

Fig. 2 is a horizontal sectional view taken on the line 22 of Fig. 1;

Fig. 3 is a view similar to Fig. 1 but illustrating a modified form of construction;

Fig. 4 is a horizontal sectional View taken on the line i-d of Fig. 3;

Fig. 5 is a fragmentary sectional view taken in I the same plane as the view in Fig. 3 illustrating more clearly the initial construction of two of the independently formed parts thereof;

Figs. 6, 'l and 8 are views corresponding to Figs. 3, 4 and 5 but of another modified form of 7 construction.

The present invention in certain respects constitutes an improvement in the valve structure and method of vmaking the same disclosed in the co-pending application for Letters Patent of the United States filed June 28, 1937 by George Charlton on Valve structure and method of forming, Serial No. 150,771, and owned by the assignee of the present invention. The Charlton application discloses a poppet valve having a main body portion of low carbon steel orother suitable material provided with a seating surface of special or desirable metal intimately bonded thereto. One suggested method of providing such valve is by surrounding that portion of the main body portion oi the valve adapted to provide the seating surface with a housing, a suitable mass of the material from which it is desired to form the seating surface, preferably in granular or like form, being contained within the housing or the associated valve, the whole being subjected to a suitable heat whereby to cause the material which is to form the valve seating portion to melt, and the whole then being subjected to centrifugal force whereby to distribute the material adapted to form the seating surface between the main body portion of the housing over that portion of the main body portion of the valve where the seating portion is desired. Th'eeffect of 'the centrifugal action in such case is maintained until the seating material has solidified and then the ,quired character to withstand the corrosive and/or erosive action of exhaust gases, or of other desired characteristics.

The above identified Charlton application also discloses a method of making a hollow' roppet valve by integrally uniting a plurality of independently formed parts to form an integral valve structure. In other words the plurality of parts are so constructed and arranged as to provide a reservoir for the granular alloy material which is preferably employed for the valve seating-surface and the parts, areso constructed and arranged that upon melting of the material and spinning of the, assembly the special alloy material will become intimately bonded to all the parts and, after being subjected to centrifugal action and solidifying, will bond all of the parts into a unitary valve structure.

This last phase of the Charlton invention is particularly valuable in connection with the forming of hollow valves and particularly hollow valves of the type adapted to enclose a suitable amount of metallic sodium or other suitable material which will melt when the valve is operating at elevated temperatures and will serve to carry heat away from the head portion thereof and dissipate it through parts in contact with the stem portion in accordance with well known practices. The above mentioned application suggests that the main body portion of the valve may be made of suitable hollow structure having an open head permitting ease in the formation and machining of the interior of the head portion of the valve, together with a closure for the open head, the granular alloy material in such case being inserted in the space provided between the closure and the main body portion of the hollow head whereby after heating the assembly sumoient to melt the alloy and subjecting it to suitable centrifugal force a seal will be provided between the main body portion and the closure which will effectively prevent leakage or escape of the cooling medium from the interior of the valve during operation of the valve under high temperatures. i

In the preferred form of valve produced in accordance with the method disclosed in the above identified Charlton application the alloying material servingto permanently secure two indeexhaust gases, normally necessitates the employ-v ment of an alloy which is relatively resistant to the conduction of heat through it, and in view of the fact that the separately-formed cover portion and main body portion of the valve are for the most part generally spaced from one another by such alloying material, the transfer of heat between the cover portion and the main body portion independently of the coolant within the valve is retarded by the alloying material. In accordance with one phase of the present invention an improvement in the construction and method of making the Charlton valve is provided whereby this trouble is overcome. In other words, in accordance with one phase of the present invention the cover portion and the main body portion are intimately connected together independently of and in addition to the connection afforded between them by the special alloying material, thus providing a direct path of heat transfer between the cover portion and the main body portion independent of the alloying material, this, of course, enhancing the ease with which the cover portion of the valve may be cooled.

Furthermore, in the said Charlton application the bond between the special alloy material and the cover portion and main body portion of the valve is relied upon entirely to prevent separation oi /these parts in addition to sealing them together. This may have the possible objection of weakening the seal in service. According, the provision of means for directly internally welding the cover and main body portions of the valve together independently of the special alloy in accordance with the present invention overcomes this possible objection in that this direct welding ill) relieves the special alloy from the necessity of performing this additional function.

In accordance with a further'phase of the present invention valves constructed in accordance with the general principles disclosed in the above identified Charlton application are provided with internal ribbing or fins within the head portion thereof, the purpose being to increase the area of heat transfer surface exposed to contact with the internal coolant so as to permit more ready dissipation of the heat in the head of the valve to the stem portion thereof through which such heat is adapted to be dissipated. This is ex tremely important for the reason that the modern tendency in aircraft engines in particular is toward an increased size of valve, the amount of increase being limited to a major extent by the ability to maintain the head of the valve below a predetermined maximum temperature. As is well understood in the art the normal operating temperatures of an uncooled valve and particularly an exhaust valve increase with the diameter of the valve and it is only possible to maintain valves having relatively large sizes of heads and in certain lines of operation below a safe operating temperature by artificially cooling them by a self-contained coolant as above described. It has heretofore been impossible, because of the methods of manufacturing commercially practical valves of the internally cooled type, to provide them with internal heat exchange ribs or fins so as, to permit any increase in the efficiency of the internal coolant. The present invention provides a simple, economical and efiicient method of providing such internal ribbing and thereby provides a method by means of which the internal coolant maybe employed at a greater efficiency than heretofore, thereby enabling valves with larger head diameters to be employed under severe operating conditions than has heretofore been possible.

Referring to the drawing and particularly to Figs. 1 and 2 a poppet valve in rough form before machining is shown as comprising a hollow stein portion l terminating at one end in an outwardly flared portion l2 formed integrally there with and forming the lower side of the head portion of the valve. The bore of the stem i0 is enlarged in the portion I2 to form a throat M which merges at its upper end with the inner wall of an annular or ring-like assembly of a plurality of spaced projections l6 arranged concentric with the bore of the stem H3 and portion H2. The axially outer face of the portion 12 radially outwardly of the ring of teeth or projections H is machined out along a curve as at It which extends radially outwardly from the projections 56 and bends axially away from the corresponding end face of the valve until it joins with a radially and axially beveled surface 20 which is bounded at its radially outward end by an axially outwardly projecting ring or collar 22 forming a portion of theperiphery of the head portion l2.

The open end of the head portion i2 is closed by a cover 24 the outer marginal portions of which rest against the axial outer face of the ring 22 and it is preferably of a convex nature as shown so as to impart a convex outer end surface to the valve head. The cover 24 on its under side is provided with a ring of teeth or projections 26, equal in number and spacing to the teeth IS. The teeth 26 are formed integrally and concentrically with the cover 24 and the inner diameter of the ring of teeth 26 is slightly greater than the outer diameter of the ring of teeth It so formed entirely independently of one another and are assembled in the manner described and then in accordance with the broad principles disclosed in the Charlton application above identified the two parts are initially secured together by welding them together around their peripheries as at 28 with the teeth or projections l6 and 26 radially aligned with each other in pairs. Then either before or after the two parts have thus been welded together as at 28 a suitable amount of granular alloying material of the type desired for a valve seating surface is introduced into the hollow interior formed between the two members, the assembly is arranged with the head portion preferably downwardly and subjected to a sulficient heating effect to cause a melting of the granular alloying material upon which the valve assembly is whirled about its axis to cause the molten alloy to be centrifugally thrown outwardly in the hollow head portion of the valve so as to completely fill the annular pocket 21 formed between the cover 24 and the surfaces I8 and 20 and to completely imbed both the rings of teeth l6 and 26 therein, and this whirling effect is continued until the alloying material solidifies. This alloying material in its solid state is indi cated at 3i! and serves to completely seal and bond the two independently formed portions of the valve together into an integral unitary structure.

In accordance with one phase of the present invention, during machining of the ring of teeth E6 on the head portion l2 the radially outer faces of the teeth it are each provided with a peripheral groove 32 of semi-circular section, and during machining of the ring of teeth 26 on the cover 24 the radially inner faces of the same are each machined to provide a circular groove 34, the grooves 32 and 34 being so constructed and arranged as to be in matching relationship when the cover portion 24 is assembled in the main body portion of the valve and with the teeth it and 26 radially aligned in pairs with each other so as to form a chamber of circular crosssectional configuration between them. The alloying material 30 in flowing into such circular chamber and being solidified therein serves to provide a pin-like portion between each pair of aligned teeth mechanically interlocking the cover portion 24 and the main body portion of the valve together against axial separation.

As previously mentioned the granular alloying material which eventually forms a solidified portion 30 sealing and joining the two parts of the valve together is preferably of a character particularly designed to resist the corrosive and erosive effects of exhaust gases and the composition of the same may be varied to obtain any desired hardness or other characteristics. It must, of course, be of such nature as to melt at a lower temperature than the material from which the main body portion of the valve and the cover 24 are formed, but this feature oifers no difficulties. Examples of a suitable composition for the material 30 will be found in the Charlton appll cation above identified.

The following compositions are representative of material which may be employed as the granular alloying material which eventually forms the solid portion til, it being understood that these examples are illustrative of the general class of materials which may be employed for this purpose and embody characteristics found desirable for the purpose specified.

Carbon 0.76% Manganese 6.14% Chromium 9.64% Silicon 0.63% Nickel 33.17% Boron; 1.87% Balance cipally iron The melting point of this alloy is apprordmately 207,5 F. With this alloy spinning can readily be done between 2150 F. and 2200 F. and it may be employed where the main body portlonof the valve and the cover portion 2 5 are made of steels having ordinary melting points. Where employed in such a way as to form. the valve seating surface it provides such surface having a hardness of approximately 35 Rockwell, C scale.

less approximate.

Carb 0.38% Silicon 0.23% Chromium 14.53% Tungsten 18.08% Boron-g. 3.5%

Balance- Principally iron The melting point of this alloy is approximately 2130 F. and successful spinning has been done with it at 2250 F. This alloy when used for the seat of the valve provides a hardness of 63 Rockwell, C scale.

When it is desired to employ a valve seat that is resistant to the corrosive and erosiv eifects of exhaust gases but is still soft enough to permit practical machiningan alloy similar to the example first given for this purposecan be used which has a machinable hardness of approximately 35 Rockwell, C scale. It will be noted that the other suitable alloy last mentioned has an approximate hardness of 63 Rockwell, C scale. The hardness of 35 Rockwell in the one case and 63 Rockwell in the other represents a wide range of hardness, from a machinable hardness to a ,very hard unmachinable state. Between this hardness range suitable alloys with varying de-' H points than the ordinary melting point of steel lies principally in the use of the element "boron. A high carbon-and silicon content has an efiect in lowering the melting point but a pronounced lowering is effected by the use of boron.

the head portion 2 5 to the main body portion of the valve the rate of heat transfer between these parts might be lower than desired In the construction shown in Figs. 1 and 2 it will be understood that the clearance shown between the rings of teeth it and 26 between the axial outer ends of these rings and the adjacent surface of the opposed parts are shown in exag= gerated form and in actual practice only suflicient space is left between these parts to insure flowing of the molten alloying material between them. Consequently in actual practice only a very thin layer of the alloying material 38] separates the above described surfaces so that particularly with the overlapped relation of the rings it and 2% a relatively large areaof heat transfer surface will exist directly between the cover portion 261 and the main body portion of the valve, thus enhancing the rapidity with which heat may be transferred between these parts.

After the valve has been completed to the condition illustrated in full lines in Fig. 1, the entire assembly is machined to bring it to the shape indicated by the dotted lines 36 which is the form desired in the finished valve. It will be noted that in machining the valve to the shape indicated by the lines 36 the welding 28 will be completely removed as well as all of the metal of the main body portion of the valve and the cover 25 radially outwardly of the pocket 2'! and that a portion of the material 39 in the pocket 2i is cut away as at 38 to form a valve seating surface of the desired size, shape and. contour. The valve seating surface 36 being formed of the material 36 which is of special characteristics designed to withstand the corrosive and/0r erosive efiects of exhaust gases, it provides an ideal valve seating surface.

It will be understood that after the valve has been completed to the degree above described the hollow interior thereof is then charged with the desired amount .of a material which will serve as an internal coolant. This is preferably metallic sodium but-may be other suitable material such for instance as any of the materials disclosed in U. S. Patent No. 1,670,964. Suchmaterial is added through the hollow stem pertion after which the stem portion is suitably.

Withthe valve completed as thus described, when the valve is operating under normal conditions and particularly where employed as an exhaust valve, the metallic sodium or other material td will melt and will be violently agitated within the interior of the valve, absorbing heat from the hollow heat portion of the valve and transmitting such heat to the stem portion of the valve where the heat will be dissipated through the valve stem guide.

It has been previously mentioned that the modern tendency toward increased cylinder sizes and, accordingly, increased valve sizes has been limited to a considerable extent by the ability to cool the engine valves and particularly the exhaust valves. It has only been possible for internal combustion engines and particularly that type thereof commonly employed in aircraft to obtain the power output developed by modern engines of this type because of the fact that commerclally practicable internally cooled valves of the self-contained coolant type have been produced in commercial'quantities. Those skilled in theart will, of course, readily understand that the larger the valve the more difficult it is to cool the same even though the valve employs an internal coolant and, accordingly, the problem of more efiiciently .cooling such valves has arisen. In accordance with a further phase of the present invention such additional cooling is obtained by providing the hollow head portion of the above type of valve with internal ribs or webs which not only serve to increase the heat transfer area internal coolant, but also to internally reinforce the valves against distortion, warpage, breaking or other defects. Prior to the advent of the Charlton invention disclosed and claimed in the co-pending application above identified no commercially practicable means for producing an internally cooled valve capable of permitting the provision of such ribs or fins has been suggested and in the only commercially practicable method of producing such valves the provision of such ribs or fins was absolutely impossible. In accordance with the present invention, however, such ribs or fins may be economically provided in a commercial practicable manner and in Figs. 1 and 2 such fins are illustrated at 42 and as being provided in the throat portion H of the valve head. Thefins 42 are, of course, formed in the throat l4 during manufacture of the main body portion of the valve and before the cover 24 is applied and they may be formed in a number of different ways. For instance the throat portion of the valve may originally be made of a thickness corresponding to that shown together with the depth of the fins and the material between the desired location of the fins removed in any suitable manner for instance as by a piercing tool or by machining in some other manner. On the other hand, during the swaging operation upon a hollow tube in order to thicken and flange one end thereof to form the head portion l2 a mandrel of the desired size, shape and contour may be inserted in the end portion of the piece of work during the hanging operation to produce the fins. In any event the fins 42 are integral with the main body portion of the valve and the heat which is transmitted to the head of the valve during operationin an internal combustion engine is transmitted to the fins which thereby offer an additional area of contact for the molten material 46 to bathe and, therefore, absorb heat from the heat portion of the valve. In Figs. 3, 4 and 5 a slightly different form of construction is illustrated although certain similar parts are indicated by the same numerals asin Figs. 1 and 2 but also carry a prime mark. In this case the main body portion 50 of the valve is identical to that shown and described in connection with Figs. 1 and 2 with the exception that the ribs 42 are eliminated as are also the ring of teeth It. The cap portion 52 in this instance is provided with a continuous annular flange or ring 54 formed integrally therewith and arranged in approximately the In accordance to the main body portion 50 of the valve by a percussion welding operation or any other suitable type of welding operation which will fuse the metal of the ring 54 into the main body portion 50 and will permit the cover 52 to be pressed downwardly until its lower outer marginal portions come into contact or into desired closely spaced relation with respect to the opposed margins of the main body portion as illustrated. The welding of the ring 54 to the main body portion 50' as above described not only serves to provide a securing bond between these two parts in addition to the alloying material 30' but also provides for a direct path of heat transfer between the cap or cover 52 and the main body portion 50 independently of the special alloy 30.

After the cap 52 and main body portion 50 are welded together in the manner above described the two are further welded together at their periphery as at 2B in the same manner as the construction explained in connection with Figs. 1 and 2. A suitable mass of special alloy which may be of any suitable or desirable type as above explained, preferably in granular form, is introduced into the hollow interior of the valve either prior to or after the cover 52 is welded to the main body portion 5.0, the entire assembly is then heated and centriiugally spun so as to distribute the molten alloying material to the outer portions of the interior of the head portion of the sembly and so as to fill the pocket 21, corresponding to the pocket 21 previously ring 54'is continuous some means must be provided to permit the molten alloying material to flow therethrough and, accordingly, the ring 54 is provided with a plurality of openings 56 therethrough for this purpose. After the assembly has been heated and rotated as above described, the heating discontinued and the rotation maintained until the alloying material 30 has solidified, the rotation is then discontinued and the assembly is machined to bring it to a finished shape such as indicated by the dotted line 36'. The metallic sodium or other internal coolant is then added and sealed in place.

In the construction shown in Figs. 3, 4 and 5 instead of providing'heat exchange ribs in the throat portion of the main body portion 58 of the vaive in accordance with the disclosure of Figs. 1 and 2, a plurality of radially disposed heat exchange ribs 53 arranged in equally angularly spaced relation are formed on the under or inner side of the cover 52 within the confines or" the ring 54. As will be apparent the ribs 58 not only serve to strengthen the cover 52 but also provide heat interchange ribs ofiering a greater area of heat exchange surface to the molten coolant within the valve during normal operation and, therefore, serve as a means for more quickly extracting heat from the heat portion of the valve nd dissipating it through the stem portion.

In Figs. 6, 7 and 8 a construction similar to that shown in Figs. 3, 4 and 5 is illustrated except that in this case both the main body portion 50' and the head portion 52' are internally provided with cooling fins or webs 60 and 62, respectively, the remainder of the construction being identical to that shown in Figs. 3, 4 and 5 and, accordingly, other parts are indicated by the same numerals except that such numerals bear a prime or double prime mark as the case may necessitate. In this case the ring 54 on the v described. In this case because of the fact the lower side of the cover 52' is initially formed in exactly the same manner as the ring 56 on'the cover 52 previously described but the ribs or fins 62 on the underside of the cover 52','instead of being of the same general shape as indicated in Figs. 3, 4 and 5, in this case have their radially outer end portions extended down into the same plane as the plane of the lower edge of the ring 56' and such lower edge is beveled off in the same manner as the lower edge of the ring 5d. Also the ribs or fins St in the throat portion of the main body portion of the valve are equal in number with respect to the ribs G2 and are arranged in complementarily spaced relationship and the upper end faces of the ribs Gil are machined off in a plane parallel with that portion of the main body portion 59' to which the ring 561' is to .be welded so that when the cover 52' is welded to the main body portion 5% not only will the ring 5 3, be welded to the main body portion 56' but the radially outer portions of both the ribs or fins Gil and 62 will be brought into matching relationship and welded together, as illustrated in Figs. 6 and 7. Thus .in this construction not only is the actual bond between the main body portion 58' and the cover portion 52' provided by such'welding materially increased in addition to that ofiered by the special alloy 30", but the actual path of direct heat flow between the main body portion 5% and cover portion 52' independently of the special alloy 39' is materially increased as is also the available surface area for the transfer of heat to the internal coolant within the interior of the valve.

It will, of course, be apparent to those skilled in the art that the construction of a valve in accordance with the present invention is capable of being modified considerably from that of the particular forms shown by way of illustra tion'and, accordingly, it will be understood that formal changes may belmade in the specific embodiments of the invention described without departing from the spirit and substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. A hollow head poppet valve comprising a pair of independently formed parts, means bonded to both of said parts exposed both externally and internally of said hollow head providing a seating surface for said valve, and means independent of the first mentioned means rigidly securing said independently formed, parts to-. gether. f

2. A poppet valve comprising a hollow main body portion having a flared end portion, a cover for said flared end portion, means formed integrally with the inner face of said cover portion welded to said main body portion, and a valve seating portion of a difierent material from said main body portion and said cover portion disposed both inwardly and outwardly of said means on said cover portion and forming a seating surface for said valve;

3. A hollow poppet valve including a separately formed main body portion having aflared end, a cover portion for said main body portion welded thereto interiorly of the outer surfaces'of said valve, and a valve seating portion formed of a material different from said main body portion and said cover portion positioned outwardly of said weld and intimately bonded to both said' main body portion and said cover portion and aaraosa J forming means in addition to said weld for securing said portions together.

4. A poppet valve comprising, in combination, ahollow main body portion having a flared end, a cover portion for said flared end, said flared 5 end and said cover portion each being provided with projections thereon and said projections being arranged in overlapping relation with respect to each other, and a valve seating portion of different material from said main body portion and said cover portion bonded to both of said portions and said projections.

5. A poppet valve comprising, in combination, a hollow main body portion having a flared end, a cover portion for said flaredend, said flared end and said cover portion each being provided with projections thereon, and said projections being arranged in overlapping relation with respect to each other, a valve seating portion of different material from said main body portion and said cover portion bonded to both of said portions and said projections, the opposed faces of said projections being provided with opposed recesses therein, and said material of" said valve seating portion filling said recesses whereby to provide a pinned joint between them.

6. A poppet valve including a stem and an enlarged head both of which are hollow, the bore of said stem flaring outwardly into the hollow interior of said head to form a threat, fins formed 30 integrally with said valve projecting inwardly from said throat, and fins formed integrally with the outer end wall of said head projecting inwardly therefrom and effecting a continuation of said fins in said throat.

7. A hollow poppet valve including an independently formed main body portion and an independently formed cover portion, said main body portion being hollow, fins formed integrally with said main body portion and projecting inwardly therein, and fins formed integrally with said cover portion welded to the fins insaid main body portion.

'8. A, hollow poppet valve including an independently formed main bodyportion and an independently formed cover portion, said main body portion being hollow, fins formed integrally with said main body p'ortion and projecting inwardly therein, fins formed integrally with said cover portion welded to the fins in said main body 50 portion, and a valve seating portion of a material difierent from said main body portion and said cover portion bonded to both of said portions.

9. A poppet valve comprising, in combination, a. hollow main body having a flared end portion, 55 a cover portion for said flared end portion, at least one of said portions having an axially directed projection spaced radially inwardly of the periphery thereof welded to the other of said portions, said, portions cooperating to provide an an annular channel therebetween lying radially outwardly of said projection, and an annular valve seating portion of a material different from said main body and said cover portion filling said channel and intimately bonded to both said m'ain 35 body portion and said cover portion, said valve seating portion being formed to present a seating surface at the open edge of said channel and providing means in addition to said weld for securing said main body portion and said cover portion 70 together. v V

ROBERT H. DAISLEY. 

